Some advice and a lot of first-hand anecdotes and observations from someone who accidentally had a career in the bike business.

Wednesday, July 18, 2012

Fuzzy pictures with a clear message

Last week we had a rash of bikes that had developed mysterious shifting problems. Adjusted derailleurs would creep out of adjustment a little more with every shift.

The fuzzy photo above illustrates how the inner wires of shift cable housing can punch through the ferrule and burrow into the brains of the shifter. They can also emerge from the other end, through the cable stop on the frame. Any section of housing in the system can do this, but it causes the most potential damage when the wires dig into the shifter.

4 comments:

I was very surprised to find my recent Jagwire re-cable kit had linear reinforcing wires (as opposed to a coil) in the brake housing, of all things. I'm not sure if they recommend a ferrule where that housing meets the brifter, (They don't include enough in the "Racer" re-cable kit to do this) but I used metal ones there. I pulled apart an older bike a few years ago where the brake lever had started to do exactly what you describe the shifter doing, and I was sure I had really screwed up and used shift housing for my brakes. Now I'm pretty sure it was just the way the kit came and I hadn't used a decent ferrule.

It's true: some in the bike world these days recommend using linear-wire housing "to make the brakes more responsive." Aieee!

Not all metal ferruels are created equal. We use Jagwire 5mm open ferrules. The ends are reinforced to take the pressure of linear wires. Cane Creek's basic metal ferrule fails rapidly when used on linear wires.

On spiral-wound casing the heavier ferrule isn't necessary, but we use it anyway because we don't want to bother with two very similar items. One good metal ferrule rules.

"Aieee!" indeed. The brake housing that blew up on me was especially heartbreaking because I had just finished a beautiful diamond weave/cloth tape/shellac taping job that I had to cut apart. Probably 25 bucks worth of handlebar stuff. -